WO2022136811A1

WO2022136811A1 - Controlled bobbin holder for a thread winding unit

Info

Publication number: WO2022136811A1
Application number: PCT/FR2021/052456
Authority: WO
Inventors: Christophe Magnier; Stéphane VILLALONGA
Original assignee: Commissariat à l'Energie Atomique et aux Energies Alternatives
Priority date: 2020-12-24
Filing date: 2021-12-24
Publication date: 2022-06-30
Also published as: FR3118452A1; JP2024502298A; US20240051243A1; CA3205783A1; FR3118452B1; EP4267500A1

Abstract

The present document relates to a device (28) for unwinding a strand from a bobbin (31), comprising: a plate (30) supporting at least one bobbin holder (32), which extends along an axis (A) substantially perpendicular to the plate (30) and is intended to receive a bobbin (31) capable of rotating about the axis of the bobbin holder (32); means (34) for translationally moving the bobbin along the axis of the bobbin holder (32); means (41) for controlling the movement means (34) and configured so as to maintain the strand (37) leaving the bobbin (31) in a substantially constant position along the axis (A) of the bobbin holder (32).

Description

Title: Driven spool holder for a filament winding installation

Technical area

This document relates to a driven spool holder for a filament winding installation capable of winding at least one wick of a spool around an object such as a hollow mandrel intended to form a reservoir that can for example receiving pressurized fluid, such as in particular gaseous hydrogen.

Prior technique

[0002] Filament winding is a method of implementation by molding composite materials in the form of parts having an axis of revolution (cylinder, cone, etc.). This process is suitable for mass production and is mainly used to manufacture parts subject to high mechanical stress (tanks, pipes, etc.).

Figure 1 shows a filament winding installation 10, according to the known technique, comprising a mandrel 12 rotatably mounted on a frame 14 and around a substantially horizontal longitudinal axis A. The installation 10 comprises a reel 16 movable in translation along the longitudinal axis A and carrying a plurality of coils 18 extending substantially perpendicularly to a panel of the reel and substantially horizontally. Each reel 18 comprises a wick 20, which are brought together contiguously next to each other at a laying head 22 so as to form a layer. The laying head 22 is integral with the reel 16 via a carriage 24 movable in translation along the longitudinal axis A.

[0004] In certain configurations (not shown), the laying head can also move in a direction transverse to the axis of the mandrel, turn around said transverse axis, pivot around the longitudinal axis, or even move on the vertical axis.

[0005] Prior to the start-up of the filament winding installation, the web is attached to the mandrel. Tensioners of the reel are activated to put the fibers under tension, limit the fogging and compact the best successive layers deposited. A layer is defined by a winding making it possible to deposit the layer on the whole of the surface of the mandrel which it is desired to cover. It is possible to create a layer of helicoidal type with the layer which is deposited by constituting helices in order to cover the whole of the surface of the cylinder and the desired zones in the hemispherical bottoms. It is possible to make a layer of the circumferential type where the sheet is deposited almost transversely to the axis of the mandrel over all or over part of the cylindrical zone of the mandrel. Structuring by filament winding makes it possible to stack a succession of helical and/or circumferential layers in order to achieve the desired mechanical performance of the object. In general, the machine is controlled by a numerical control. This numerical control is often programmed by an operator using software dedicated to filament winding.

[0007] Contact laying machines are known which allow the laying of strips of short length without the risk of twisting. However, these machines do not allow removal and maintenance of a long continuous fiber under tension or axial mechanical stress in the direction of the fiber which is imposed and regulated.

Known processes of this type are ATL for Automated Tape Layer and AFP for Automated Fiber Placement.

[0009] The ATL process uses wide ribbons (generally from 100 to 300 mm). This technique allows removal on surfaces with a small radius of curvature and large dimensions such as the wing of a civil aircraft. The AFP process performs a juxtaposition of tape less than 10 mm wide and an assembly at the head outlet of up to 32 tapes.

[0010] The main applications are the production of flat parts or parts with a large radius of curvature. The main idea is to replace the human hand for laying down successive folds with defined fiber orientations.

[0011] All current systems use calibrated prepreg tapes (fiber/resin) with a separation film between the layers on the storage reel. These calibrated tapes come from unidirectional pre-impregnated plies recut with the risk of partial cutting of the reinforcement on the edges. Material costs are high here and it is necessary to have a system for winding the separation film during draping operations.

[0012] None of these systems uses standard preimpregnated fibers, that is to say without a separation film between the layers for implementation by filament winding. It is not possible to apply a continuous tension (or constraint) in traction (in the direction of the fibre) on the rovings since the rovings constituting the sheet are cut at each end of the part produced.

[0013] To date, the successive developments in the field of the implementation of composite materials are for a large volume concentrated on the automation of processes. These developments are driven by the significant needs expressed in the automotive and aeronautic sectors. The development of hydrogen storage technologies (for example at 700 bar operating pressure) with the increase in the gravimetric capacity (that is to say the ratio between the quantity of hydrogen stored and the mass of the container), pushes the limits of use of composite materials.

[0014] Conventional filament winding processes (dedicated machines) and more robotic ones (versatile machines) have never taken into account the full impact of the process on the loss of performance. In most cases, the coil support is far from the placement head and the rovings pass through a large number of deflections and rollers before arriving at the placement head.

[0015] Currently systems for unwinding rovings (from reels that store the material) on filament winding machines are made without taking into account the effects of unwinding on the geometry and the mechanical performance of the roving. Most of the systems, whether mechanical (fixed adjustment of the tension applied to the wick) by springs or belt or electronic (modulated adjustment of the tension applied to the wick), are simple systems for unwinding the wick from the reel . However, the wick of each coil is wound on the rod of the coil with a shearing angle which induces a movement of the wick along the rod of the coil. When the guide member at the coil outlet is a return rod, it is understood that the wick moves along the rod. When the guide member at the coil outlet is a deflection roller, the wick forms an oscillating angle around 90°. In either case, the movement of the bit relative to the return device is likely to twist the bit, which can lead to manufacturing defects when placing the bit on the chuck.

[0016] This problem is further increased when the coil wick is pre-impregnated with a curable partially polymerized matrix such as a thermosetting matrix or a thermoplastic matrix. Indeed, the stickiness greatly limits or even makes it impossible to slip the wick, which prevents any movement that limits the formation of a spin when it is initiated.

[0017] To limit the formation of spins, it is known to move the coils away from the deflection members and therefore from the laying head, which poses a problem of footprint of the filament winding machine.

Summary

[0018] A device for unwinding a wick from a coil is proposed, comprising: a plate carrying at least one bobbin holder extending along an axis substantially perpendicular to the plate and intended to receive a coil capable of rotating around said spool pin; means for moving the spool in translation along the axis of the spool holder means for controlling the moving means configured to allow the spool exiting the spool to be held in a substantially constant axial position, that is to say i.e. along the axis of the spool holder.

[0019] The control of the movement of the reel makes it possible to preserve the geometry of the wick of the reel which is unwound. It is understood that the axial position of the coil is not strictly constant in the mathematical sense of the term but is maintained substantially constant so that its position appears constant and prevents the formation of spins.

[0020] The coil may be a coil of roving formed from a plurality of reinforcing fibers or filaments. The fibers may be carbon fibers.

[0021] The moving means may comprise means for guiding in translation a connecting piece along an axis parallel to the axis of the reel holder, this connecting part being connected to a reel support surrounding the reel holder. , the spool support being coupled in rotation to the spool holder and free in translation along the spool holder.

[0022] The connecting piece can be connected in rotation about the longitudinal axis to the coil support and be integral in translation along said axis of said coil support.

[0023]According to another characteristic, the guide means may comprise at least one rod substantially perpendicular to the plate and in which the connecting piece is slidably guided.

[0024] The displacement means may comprise a motor coupled in rotation by a belt to an endless screw driving the connecting piece in translation.

The spool holder can be rotatably mounted relative to the connecting piece.

[0026] A rolling bearing can be mounted at the junction of the coil support and the connecting piece.

The spool holder includes ball bearings for the translational movement of the spool holder.

The spool holder can be rotatably mounted on the plate.

[0029] The control means may comprise means for detecting the axial position of the coil outlet wick.

[0030] The detection means may comprise two position sensors, for example of the optical or other type, spaced axially from one another and configured to detect the passage of the drill bit. [0031] Winding installation of at least one wick of a coil by means of a device according to one of the preceding claims.

Brief description of the drawings

[0032] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

[Fig. 1] Figure 1, already described above, is a schematic perspective view of a filament winding installation according to the prior art;

[Fig. 2] figure 2 and

[Fig. 3] Figure 3 are schematic perspective views in two different orientations of a device according to this document;

[Fig. 4] Figure 4 is a schematic perspective view of the spool holder with an enlargement in the right part of the part framed in dotted lines;

[Fig. 5] Figure 5 is a perspective diagram of a spool holder and a spool holder surrounding the spool holder;

[Fig. 6] Figure 6 is a schematic view similar to that of Figure 5 in which the spool holder has been removed;

[Fig. 7] Figure 7 is a schematic perspective view of the spool holder with an enlargement in the right part of the part framed in dotted lines, a partial section being made to show the connection between the connecting piece and the spool holder;

[Fig. 8] Figure 8 is a schematic perspective view of a reel unwinding device mounted on a reel holder which is in a first position in Figure 8A and in a second position 8B.

Description of embodiments

Referring now to Figure 2 which shows a device 28 is unwinding according to this document and which comprises a plate 30. It is observed that a coil 31 is carried by the plate 30 and on a side which is opposite to that intended to support a laying head (not shown).

The plate 30 thus includes a coil 31 but could carry several. The coil(s) 31 extend along a longitudinal axis A which may be parallel to the longitudinal axis of the laying head. Reference will now be made to a single coil 31 although the plate 32 may comprise several. The device 28 comprises a spool holder 32 surrounded by a support 36 of the spool 31, the spool 31 being mounted integral in rotation with the support 36 of the spool 31, for example by a clamped mounting or any other suitable mounting. The spool holder 32 and the spool support 36 are coaxial along an axis A substantially perpendicular to the plate 30.

The device 28 comprises means 34 for moving the coil 31 in translation along the axis A of the spool holder 32 and means 41 for controlling the moving means configured to allow the wick 37 to be held (FIG. 8 ) of the coil 31 at a substantially constant axial position.

The displacement means 34 comprise means for guiding in translation a connecting piece 38 connected to the support 36 of the coil 31. This connecting piece 38 comprises an upper part 38a for sliding in translation through which two rails 40 or guide rods parallel to the longitudinal axis A of the reel holder 32. The upper part 38a is able to slide on the two rails 40. The upper part 38a of the connecting piece 38 is connected to a bracket 38b whose end opposite to the upper part 38a is connected in rotation to the support 36 of the coil 31 and is fixed in translation along the said axis A of the said support 36 of the coil 31 as will appear better in relation to FIGS. 4 to 7. The displacement means 34 include a motor 42, the output shaft 44 of which is coupled in rotation by a belt 46 to a worm 48 driving the connecting piece 38 in translation. More particularly, the endless screw 48 passes through the upper part 38a of the connecting part 38 and is coupled in rotation thereto via a thread so that the rotation of the screw 48 causes the movement in translation along the longitudinal axis A of the connecting part 38 and consequently of the support 36 of the coil 31 and therefore of the coil 31 .

In Figure 3, we observe the presence of a motor 45 intended to generate a voltage in the wick 37 of the coil 31. The output shaft 47 of this motor 45 is coupled to the spool holder 32 by a belt 50. A tensioner could be used to slit the belt 46 and/or the belt 50.

Referring now to Figures 4, 5 and 6 which illustrate the support 36 of the coil 31 coupled in translation to the bracket 38b of the connecting piece. The support 36 of the reel 31 is mounted in translation along the longitudinal axis A on the reel holder 32 and is capable of sliding along said longitudinal axis A on the reel holder 32. The support 36 of the reel 30 is coupled in rotation to the spool holder 32 via corresponding shape. More specifically, the internal face of support 36 of reel 31 comprises longitudinal ribs 36a engaged in longitudinal grooves 32a of reel holder 32. Reel holder 32 comprises ball bearings 50 for translational movement of the support 36 of the spool 31 on the spool holder 32. In this way, the spool holder 32 is connected in rotation to the support 36 of the spool which carries the spool 31 and the support 36 of the spool 31 can slide on the spool holder 32.

To ensure rotation of the support 36 of the coil 31 relative to the connecting part 38 which is fixed in rotation, a bearing is formed at the annular junction of the bracket 38b and the support 36 of the coil 31. This bearing can be formed by an annular flange 52 of the support 36 of the coil 31 which is mounted in an annular groove of the bracket 38b. It can thus be a plain bearing. It would also be possible to make a connection by a rolling bearing with an outer ring secured to the bracket 38b and with an inner ring secured to the support 36 of the coil 31 (Figure 7).

In order to ensure control of the motor 42 for the translational movement of the support 36 of the coil 31, the control means 41 comprise means 41a for detecting the axial position of the wick 37 at the output of the coil 31, these detection means comprising for example two optical position sensors 41a spaced longitudinally from each other and configured to detect the passage of the wick 37. These optical sensors 41a can be carried by a rod 54 parallel to the axis longitudinal A (figure 8).

[0042] Figure 8 illustrates two positions along the axis A of the coil 30 and therefore of the support 36 of the coil 30. It is observed that with the device 28 according to this document, the wick 37 always comes out of the coil 31 in a direction substantially perpendicular to the axis of the coil. The position of the bit along the longitudinal axis remains constant, which makes it possible to use a deflection roller or a deflection rod 56 without risk of spin formation.

Claims

-8-Claims

[Claim 1] Device (28) for unwinding a roving from a coil (31) comprising: a plate (30) carrying at least one coil carrier (32) extending along an axis (A) substantially perpendicular to the plate (30) and intended to receive a spool (31) able to rotate around said axis of the spool holder (32); means of movement (34) in translation of the reel along the axis of the reel holder (32); control means (41) displacement means (34) configured to allow maintenance of the wick (37) exiting the coil (31) at a substantially constant position along the axis (A) of the holder coil (32).

[Claim 2] Device according to claim 1, wherein the moving means (34) comprise means for guiding in translation a connecting piece (38) along an axis parallel to the axis of the reel carrier (32) , this connecting piece (38) being connected to a spool support (36) surrounding the spool holder, the spool support (36) being coupled in rotation to the spool holder (32) and free in translation along the spool holder -coil (32).

[Claim 3] Device according to claim 2, in which the connecting part (38) is connected in rotation about the longitudinal axis (A) to the support (36) of the coil and is integral in translation along the said axis (A ) of said spool holder (36).

[Claim 4] Device according to claim 2 or 3, wherein the guide means comprise at least one rod (40) substantially perpendicular to the plate (30) and in which the connecting piece (38) is slidably guided.

[Claim 5] Device according to one of Claims 2 to 4, in which the displacement means (34) comprise a motor (42) coupled in rotation by a belt (46) to a worm screw (48) driving in translation the connecting part (38).

[Claim 6] Device according to one of Claims 2 to 5, in which the spool holder (32) is rotatably mounted relative to the connecting piece (38).

[Claim 7] Device according to Claim 6, in which a rolling bearing is mounted at the junction of the reel support (36) and the connecting piece (38).

[Claim 8] Device according to one of Claims 2 to 7, in which the bobbin holder (32) comprises ball bearings for the translational movement of the bobbin holder (36). -9-

[Claim 9] Device according to one of the preceding claims, in which the bobbin holder (32) is rotatably mounted on the plate (30).

[Claim 10] Device according to one of the preceding claims, in which the control means (41) comprise means (41a) for detecting the axial position of the wick (37) output from the coil (31).

[Claim 11] Device according to claim 10, in which the detection means (41a) comprise two position sensors, for example optical, spaced axially from each other and configured to detect the passage of the bit (37) .

[Claim 12] Installation for winding at least one sliver of a bobbin by means of a device according to one of the preceding claims.